COUNTY REPORT IA

Plymouth County, Iowa

9 ZIP codes · Avg score 64/100 · Grade C · Updated 2026-06-04

Within Plymouth County, safety data across 9 ZIP codes suggests a fair but uneven system — violations are present and worth checking at the ZIP level.

How Plymouth County Compares

Plymouth County64/100
Iowa avg59/100
National avg68/100

How Plymouth County Compares

C
County Grade
64/100
Avg Safety Score
9
ZIP Codes
8
Water Systems

Plymouth County scores 5 points above the Iowa state average (59/100) and 4 points below the national average (68/100).

Data: EPA SDWIS Last verified: 2026-06-04

C
County Grade
64
Avg Safety Score
9
ZIP Codes
Best ZIP: 51031 (70/100)
Lowest ZIP: 51011 (40/100)
$195K
Median Home Value
$2,067
Avg Remediation (106% of home value)

ZIP Code Risk Map

Water Quality Map: Plymouth County, Iowa

Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.

A B C D F

Key Risk Factors

Health risk index: 13.1 (asthma 9.7%, diabetes 11%)

Estimated additional annual cost per homeowner: $772, driven primarily by water_lead

Infrastructure: 0.466% avg pipe failure probability, 89% of ZIPs at high risk

73.9% of homes built before 1978 (lead paint era)

County Health Indicators vs National Average

Asthma 9.7% (national: 8.9%)
Diabetes 11% (national: 10.5%)
Obesity 38.7% (national: 32.4%)

Black markers indicate national averages. Source: CDC PLACES, Census ACS.

Infrastructure Overview

1968
Median Build Year
73.9%
Pre-1978 Housing
47%
Pipe Failure Probability
89%
ZIPs at High Infra Risk
High
Lead Pipe Risk

Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.

Compound Risk Breakdown

Estimated additional annual cost per homeowner: $772

Water / Lead $317/yr
Energy Code Gap $300/yr
Flood $156/yr

Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).

Housing Age Distribution

9,569 housing units in Plymouth County

Pre-1940 27%
1940–1959 14%
1960–1979 25%
1980–1999 19%
2000+ 15%

Source: U.S. Census Bureau ACS B25034 (Year Structure Built).

Water Safety Affordability

How much it costs to fix water issues relative to home values in Plymouth County

$195K
Median Home Value
$2,067
Est. Remediation Cost
1.1%
of Home Value
Remediation as % of home value low burden

Remediation costs are relatively manageable for most homeowners in Plymouth County, representing a small fraction of property value.

Remediation includes water filtration, lead abatement, radon mitigation, and flood protection where applicable. Source: Census ACS, EPA SDWIS.

Health Outcomes vs National Average

CDC PLACES data for Plymouth County residents

Asthma 9.7% (US avg: 8.9%)
Diabetes 11% (US avg: 11%)
Obesity 38.7% (US avg: 32.4%)

Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.

Water Systems with Most Violations

Top 5 systems in Plymouth County ranked by EPA violation count.

# Water System Population Violations
1 Oyens Water Supply 92 4
2 Remsen Municipal Utilities 1,678 3
3 City of Akron, 1,558 2
4 Hinton Water Supply 935 2
5 Merrill Municipal Water Supply 717 1

8 total water systems serve Plymouth County.

All ZIP Codes in Plymouth County

9 ZIP codes tracked in Plymouth County.

# ZIP Code City Safety Score Grade Violations Home Value
1 51031 Le Mars 70 B 0 $209K
2 51038 Merrill 70 B 1 $182K
3 51062 Westfield 70 B 0 $284K
4 51045 Oyens 66 C 1 $155K
5 51024 Hinton 65 C 2 $317K
6 51050 Remsen 65 C 3 $219K
7 51001 Akron 63 C 2 $178K
8 51008 Brunsville 63 C 0 $136K
9 51011 Chatsworth 40 D 0

Recommended Buyer Guides for Plymouth County

Methodologically, the recommendation order reflects severity in the federal record: contaminants flagged in EPA detection records for this county outrank generic water concerns, FEMA-confirmed hazard ratings shift emergency-related categories upward, and CDC lead-exposure markers govern when lead-test kits and certified filters appear at the top of the list.

Overview

Plymouth County in Iowa covers 9 ZIP codes with an average Home Safety Score of C (64/100).

5 of 9 ZIP codes have recorded EPA violations. All violations are monitoring/reporting type.

← Back to Iowa water quality report

Data Sources

Updated daily.

Frequently Asked Questions

Is water safe in Plymouth County?
Plymouth County receives a grade of C. Some ZIP codes have recorded violations and residents in affected areas may want to test their water.
How many water systems serve Plymouth County?
Plymouth County is served by 8 public water systems that supply drinking water to residents across 9 ZIP codes.
What is the biggest environmental risk in Plymouth County?
The primary environmental risk factor in Plymouth County is water_lead. This contributes to an estimated additional annual cost of $772 per homeowner.
How old are homes in Plymouth County?
The median home build year in Plymouth County is 1968. 73.9% of homes were built before 1978, which means they may contain lead-based paint and older plumbing materials.
How does Plymouth County compare to Iowa?
Plymouth County has an average water safety score of 64/100, which is above the Iowa state average of 59/100.

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